A Program Project which proposes: 1) To complete the isolation, molecular characterization and synthesis of a novel pituitary and placental protein, mesotrophin, or mesodermal growth factor (MGF) present in bovine and human pituitaries and human placenta; 2) To ascertain the biology and role of MGF in function of the corpus luteum, implantation and fetal developmnt; 3) To elucidate the nature of the hypothalamic control of the secretion of MGF which we already have demonstrated to exist; 4) Complete the isolation, characterization and synthesis of inhibin of follicular fluid origin; 5) To ascertain the biology of follicular inhibin(s); 6) To elucidate the nature of follicular peptides regulating follicular sensitivity to gonadotropins; 7) To pursue physiological studies with synthetic GRF (growth hormone releasing factor or somatocrinin), in vivo and in vitro; 8) To isolate, characterize and synthesize pituitary factors (other than ACTH) involved in control of pubertal adrenal androgenesis; 9) To improve the sensitivity of the current methodology for characterization of peptides; 10) To maintain or expand the current methodology for peptide synthesis; 11) To maintain and expand the current methodology for radioimmunoassays and immunotechniques; the latter three projects as part of core supports within the Program.